AU609832B2

AU609832B2 - Preparation of polymer polyols

Info

Publication number: AU609832B2
Application number: AU18487/88A
Authority: AU
Inventors: Werner August Lidy; Huy Phan Thanh
Original assignee: Polyol International BV
Current assignee: Polyol International BV
Priority date: 1984-04-24
Filing date: 1988-06-29
Publication date: 1991-05-09
Anticipated expiration: 2005-04-23
Also published as: US4831076A; EP0162588B1; FI851616L; EP0162589B1; PT80337A; EP0162589A1; NO164357B; KR850007439A; AU576581B2; ES542497A0; FI85592C; DK609485A; AU1848788A; DE3584469D1; JPH0649149A; PT80338A; DK182085D0; ES8705005A1; DE3568053D1; ES549245A0

Abstract

A modified polyol, suitable for use as a non-aqueous dispersant in the preparation of polymer/polyols containing high levels of polymer, is provided. The modified polyol comprises the product obtained by reaction of a polyol with a coupling agent having at least two functional groups which are reactable with hydroxyl groups on the polyol. Suitable coupling agents include silicon compounds having two such functional groups, organic compounds having two or more alkoxy groups, saturated dicarboxylic acid derivatives, alkyl or aryl esters of carbonic acid, alkyl or aryl sulphonates, boric acid or its esters and titanates.

Description

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COMMONWEALTH OF AL4 In m PATENTS ACT 1'?U o 1 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl.: Application Number: Lodged: 000 00 0 o 0 0 0 0 0 6 0 000 Complete Specification-Lodged: Accepted: Lapsed: Published: Priority: Related Art: This document cnan h amendments mnade under Section 49 and is correct for printing.I TO BE COMPLETED BY APPLICANT Name of Applicant: Address of Applicant:, Actual Inventor: Address for Service:

B-P-CHEM-&A±-S-LIMITED-

Belgrave-House, 76-Buckinghamr-Palace-Road, L-ondon-SW-1W-OSUENGL-A-ND

R

WERNER AUGUST LIDY and H-UY PHAN eC THANH y GRIFFITH HASSEL FRAZER <y4' r 71 YORK STREET SYDNEY NSW 2000

AUSTRALIA

Complete Specification for the invention entitled: PREPARATION OF POLYMER POLYOLS The following statement is a full description of this invention, Including the best method of performing it known to me/us:- 5864A/ls COMMONWEALTH OF AUSTRALIA 5864A/ls ppijATON ACCEPTED AND AMENDMENTS .LLO W ED r* Case5719(2) 1A o PREPARATION OF POLYMER POLYOLS o o 0 Soo S" The present invention relates to novel modified polyols which can be used in the preparation of polymer/polyols, sometimas termed pol;ymeric polyols or graft polyols. The present invention also 0 relates to processes by which such modified polyols are prepared and o a to processes which produce and use the polymer/polvols derived from the modified polyols. In particular the present invention relates So o Po is to novel modified polyethe rand their use in the above applications.

So°" The reaction between a polyfunccional isocyante and a polyfunctional alcohol to produce polyurethane foams, elastome-", 10 resins and the like is a well known chemical reaction which is commercially exploited on a large scale. Commercial polyurethaac manufacture in general involves the reaction between a polyfuntiona isocynate and a polyfunctlonal alcohol such as a S* polyether polyol. Such polyether polyols are made from a polyfunctional low molecular weight alcohol onto which has been added a polyalkylene oxide chain. The polyalkylene oxide chain is typically prepal;£d from ethylene oxide, propylene oxide or a mixture thereof in a Candom or block form.

In recent years, the use of polyether polyols of the type described above has been in, some areas superseded by polyether polyols contaiing additional polymeric matter. These polyether polyols, known as polymer/polyols have been described in US 3,304,273, US 3,383,351, US Reissue patent 28,715 and US Reissus patent 29,118. In gene'al, such polymer/polyols have been prepared by polymerising one or more olefinically unsaturated monomers GRIFFITH HASSEL FIAZER, SYDNEY, AUSTRALIA 5864A/ls dispersed in the polyether polyol in the presence of a free radical catalyst. The polymer/polyols produced by this process, which are thought to comprise a polymer or copolymer of the monomers at least partially grafted to the polyether polyol, have the important advantage of importing to the final polyurethane improved load-bearing properties as compared with earlier polyether polyols.

The need to obtain polyurethanes with further improved load-bearing properties has meant that recently attempts have been made to improve polymer/polyols further. In particular develonments i0 of polymer/polyols has centred around increasing the polymer c._.int whilst still maintaining the polymer/polyol in the form of a low 0o viscosity fluid having a resistance to polymer sedimentation.

00 In order to produce stable low viscosity polymer polyols, it 0 0 o 0o has been proposed to introduce during the polymerisation an extra component termed a non aqueous dispersant (NAD) stabiliser. The NAD 00°, stabiliser comprises a polyol or polyether polyol, containing o deliberately added unsaturatio- which copolymerises or grafts to the growing polymer chains thereby formfng a steric hinderance which prevents the agglomeration of particles.

An example of ouch an NAD stabiliser is given in US 3,823,201 where there is disclosed an unsaturated polyecher polyol obtained by 0000 the reaction of a polyether polyol with the anhydride of an 0° unsaturated acid, for example maleic anhydride. In this case, the anhydride of the unsaturated acid reacts with a free hydroxyl group on the polyether polyol to produce a polyecher polyol having from about 0.10 to 0.70 mole of unsaturation per mole of polyol.

0o Similar methods of introducing ursaturation into a polyether polyol thereby forming a NAD stabiliser are disclosed in S US 4,198,488, GB 1,411,646 and EP 6605f It has now been found that polymer/polyols having favourable viscosity and resistance to sedimentation at high solids conte.i can be prepared by polymerising one or more monomers having olefinic unsaturation in a polyol containing a novel NAD stabiliser.

1-

I

Accordingly, in a first aspect, the present invention provideo a process for preparing a modified polyol suitable for use as a NAD stabiliser comprising reacting a polyol with a coupling agent, wherein the coupling agent an organic compound having two or more alkoxy groups, halide groups, carboxylic acid groups, carboxylic acid halide groups, carboxylic acid ester groups, carbonic acid ester groups, alkyl sulphonate groups or aryl sulphonate groups.

In a second aspect, the present invention provides a modified polyol prepared the above process which is suitable for use as a NAD stabilise It is a feature of such NAD stabilisers thiat, asing a coupling agent having at least two functional groul. which are reactable with hydroxyl groups, the need to have any additional unsaturation in the coupling agent is avoided. Additional unsaturation however can also be present if desired to improve further the characteristics of the final NAD stabiliser.

The mechanism by which the NAD stabilisers of the present invention act is not understood in any detail.

However, without being held to a particular mechanism, it is though- that the coupling agent couples together polyol molecules to form an extended network. Such a network is able, during the preparation of a polymer/polyol, to prevent aggregation of polymeric material into particles large enough to sediment or modify the viscosity of the final product.

The polyols used in the preparation of the NAD stabiliser are preferably polyalkylene polyether polyols, polyhydroxyl containing polyesters, polyhydroxy terminated I .30 polyurethane polymers, polyhydric polythioethers, and the Slike. A preferred class of polyol is the polyalkylene Spolyether polyols, usually called polyether polyols, of which the following sub-classes are the most preferred alkylene oxide adducts of non-reducing sugars and their derivatives alkylene oxide adducts of polyphenols alkylene oxide adducts of polyhydroxyalkanes.

.7S/JM -3- -1 The polyether polyol used preferably has a number average molecular weight in excess of 400 and a hydroxyl number in the range 20 to 280. Terms such as number average molecular weight and hydroxyl number will be familiar to those skilled on the art.

Most preferably the polyether polyol is a poly(ethylene oxide and/or propylene oxide) adduct of one of the following polyhydric alcohols; glycerol, trimethylolpropane, diethylene glycol, the isomeric butanetriols, pentane'jiols and hexanetriols, and pentaerythritol.

As regards the coupling agent this ctn, in principle, be any molecule having two or more functional groups which are able to react ;ith the hydroxyl groups on the polyol providing that the coupling agent itself is not further degradable or decomposable by the polyol or under the conditions of the coupling reaction.

The coupling agent of the present application is an orc. nic compound having two or more alkoxy, groups halide groups, carboxylic acid groups, carboxylic acid halide 20 groups, carboxylic aciO ester groups, carbonic acid ester groups, alkyl or aryl sulphonate groups, and the like.

Functional groups such as anhydrides, which react with two hydroxyl groups, can be used even in the absence of unsaturation.

One particular class of such coupling agents are 0° compounds containing two or more alkoxy groups. Examples of such compounds include tecraalkyloxyalkanes e.g.

tetramcthylorthocarbonate and tetraethylorthocarbonate, trialkoxyalkanes e.g. triethoxyorthofornate and dialkoxyalkanes having the formula (R 1

(OR

2

(OR

3 where R, R R and R are independently alkyl or aryl hydrocarbyl radicals having preferably less than 20 carbon atoms and where R and R 1 ray also be hydrogen atoms. An example of these compounds is 1,1-dimethoxy ethane.

Typically the NAD stabiliser is prepared by reacting the coupling agent with the polyol in an inert solvent, for example toluene, at a temperature in the range 60 to 160°C, -4preferably 100 to 120°C. The reaction is preferably carried out in the presence of a transesterification or transetherification catalyst for example, trifluoroacetic acid/sodium acetate mixtures or an amidine or guanidine catalyst. When an acid catalyst is used it may be necessary to add a neutralisation agent, for example sodium bicarbonate, at the end of the reaction.

The NAD stabiliser produced by reactions of the type dnpcribed above have preferably a viscosity in the range 500-4000 cps a't 25"C. In addition the NAD stabiliser should have less than 0.8% by weight preferably 0.3 to 0.7% by weight induced unsaturation.

As mentioned earlier, the modified polyols described above are particularly useful for preparing polymer/polyols containing high levels of polymer. Accordingly, in a third a aspect the present invention provides a fluid polymer/polyol o prepared by polymerising, in the presence of a free radical I i catalyst, one or more monomers in a liquid polyol under o polymerisation conditions wherein the liquid polyol comprises a base polyol and a modified polyol of the type S described above.

The base polyol used in the preparation of the polymer/polyol may be any of the polyols described earlier in relation to the NAD stabiliser or a mixture thereof. The o o base polyols preferably have viscosities in the range 100-5000 centipoise at ambient temperature, more preferably i in the range 100-2000 centipoises.

During the preparation of the polymer/polyol, a polymer is produced in the liquid base polyol by polymerisation of the monomer or monomers. The monomers used are suitably vinyl monomers for example styrene, acrylonitrile, methacrylonitrile and methyl methacrylate. Preferably a mixture of styrene and acrylonitrile are used to produce a copolymer. The final polymer/polyol is suitably /tFC RN.

.7S/JM F i l__ili-L;~ili~_iiii -6one having more than 20% by weight polymer present and is preferably one having between 30 and 70% by weight polymer. As regards the relative amounts of styrene and acrylonitrile in the copolymer it is desirable for reasons of cost to be able to maximise the level of styrene present. Preferably the copolymer should contain 50 to 100% styrene on a molar basis.

The polymerisation reaction occuring during the preparation of the polymer/polyol is initiated by means of a free radical initiator. The free radical initiator can be any of those which are S 10 routinely used in vinyl polymerisation reactions including peroxides, perborates, persulphates, percarbonates and azo compounds. Typical examples of such free radical initiators include 0alkyl and aryl hydroperoxides, dialkyl and diaryl peroxides, dialkylperoxydicarbonates and azobis(nitriles). Preferred free radical initiators are azobiu(isobutyronitrile) and bis(4-tertbutyl cyclohexyll peroxydicarbonate (Perkadox).

O The polymer/polyols produced using the NAD stabilisers of the present invention are useful in the preparation of polyurethanes, particularly polurethane foams. Such polyurethane foams have 20 improved tensile strength and load bearing without impairment of the other physical parameters associated with the product. Accordingly there is also provided a process for the production of a polyurethane foam by reacting a polyfunctional isocyanate with a °o polymer/polyol of the type described above in the presence of a catalyst for the urethane forming reactio, a blowing agent and a foam stabiliser Polyfunctional isocyanates which can be used to advantage include diisocyanatoalkanes, e.g. 1,2-diisocyanatoethane, i,3-diisocyantopopane, the isomeric benzene, xylene and toluene diisocyanates, MDI and the like.

Catalysts which can be used to accele;rte the urethane forming reaction will likewise be familiar to those skilled in the art.

These include amines, phosphines, strong inorganic bases, titanace, silicate and stannate esters and organo tin derivatives.

As regards blowing agents and foam stabilisers the range of materials which can be used will be familiar to the skilled man. Thus suitable blowing agents include water and halogenated hydrocarbons of low molecular weight.

The process may be carried out batchwise or continuously.

The invention is now illustrated by the following example.

Preparation of NAD stabilisers Example 1 Triethylorthoformate as coupling agent A one litre vessel fitted with a mechanical stirrer, a thermometer and a Dean Stark apparatus lopped by a condensor was charged with a blend of polyether (500 g, glycerol started, P0:86%, EO:14%, MW:3500, OH Number:46.0 mg KOH/g.

BP Product: Polyurax U10-01) and toluene (200 ml). Residual 0j 0 water in the polyol was removed by azeotropic distillation.

To this blend, was added trifluoroacetic acid (0.7 g, 6 mmoles), potassium acetate (0.35 g, 3.5 mmoles) and triethylorthoformate (14.1 g, 95 mmoles).

The reaction mixture was then heated to 110*C for hou At 110°C a toluene/ethanol azeotrope started to boil an,i was removed by distillation through the Dean Stark apparatus. The mixture was then neutralized with sodium bicarbonate (5 g, 59 mmoles). Solvent was then removed and 25 the product filtered. It had a viscosity of 84000 cps at 25"C, an OH number of 33.9 mg KOH/g and an average MW of 14200.

S0a 0 .7S/JM1 -7-

Claims

1. A process for preparing a modified polyol suitable for use as a NAD stabiliser comprising reacting a polyol with a coupling agent, wherein the coupling agent is an organic compound having two or more alkoxy groups, halide groups, carboxylic acid groups, carbQxylic acid halide groups, carboxylic acid ester groups, carbonic acid ester groups, alkyl sulphonate groups or aryl sulphonate groups.

2. A process as claimed in claim 1 wherein the coupling agent is an organic compound having two or more alkoxy groups.

3. A process as claimed in claim 2 wherein the coupling agent is selected from the group consisting of trialkyl orthoformates, trialkoxyalkanes and dialkoxyalkanes.

4. A process as claimed in claim 2 wherein the coupling agent is selected from the group consisting of tetramethylorthocarbonate, tetraethylorthocarbonate, 1,1-dimethoxy ethane and triethoxyorthoformate. A process as claimed in any one of the preceding claims wherein the polyol is selected from the group consisting of polyether polyols, polyhydroxyl containing polyesters, polyhydroxy terminated polyurethane polymers and polyhydric polythioethers.

6. A process as claimed in claim 5 wherein the polyol is a polyether polyol having a number average molecular weight in excess of 400 and a hydroxyl number in the range o949 from 20-280.

7. A process as claimed in claim 6 wherein the polyether polyol is a poly (ethylene oxide and/or propylene oxide) adduct of a polyhydric alcohol selected, from the group consisting of glycerol, trimethylolpropane, diethylene glycol, isomeric butanetriols, pentanetriols, hexanetriols, and pentaerythritol.

8. A process as claimed in any one of the preceding claims wherein the coupling agent is reacted with the polyol in an inert solvent at a temperature in the range from 60 to 160*C. -8- i so 4* 4s 0 41 i #4*4 4 4 4 44 4 444 4

9. A process as claimed in claim 8 wherein Lhe temperature is in the range fom 100 to 120*C. A process as claimed in claim 8 or claim 9 wherein the solvent is toluene.

11. A process as claimed in any one ol claims 8-10 wherein the reaction is carried out in the presence of a transesterification or transethe:cification catalyst.

12. A process as claimed in claim 11 wherein the catalyst is a trifluoroacetic acid/sodium acetate mixture of an amidine or guanidine catalyst.

13. A process as claimed in claim 1 substantially as herein described with reference to the example.

14. A modified polyol prepared by a process as claimed in any one of the preceding claims.

15. A modified polyol as claimed in claim 14 having a viscosity in the range from 500 to 4,000 cps at

16. A modified polyol as claimed in claim 14 or claim having less than 0.8% by weight induced unsaturation.

17. A modified polyol as claimed in claim 16 having 20 0.3 to 0.7% by weight induced unsaturation.

18. A fluid polymer/polyol dispersion prepared by polymerising, in the presence of a free radical catalyst, one or more monomers in a liquid polyol under polymerisation conditions wherein the liquid polyol comprises a base polyol 25 and a modified polyol as claimed in any one of claims 14-17.

19. A fluid polymer/polyol as claimed in claim 18 wherein the base polyol is selected from the group consisting of polyether polyols, polyhydroxyl containing polyesters, polyhydroxy terminated polyurethane polymers and polyhydric polythioethers. A fluid polymer/polyol as claimed in claim 18 or claim 19 wherein the base polyol has a viscosity in the range 100-5000 cps at

41. A fluid polymer/polyol as claimed in any one of claima 18-20 wherein the monomers used in th pLolymerisation reaction are styrene and acrylonitrile. 0 435,i7S/JM -9- 22. A fluid polymer/polyol as claimed in claim containing more than 20% by weight polymer. 23. A fluid polymer/polyol as claimed in claim containing between 30 and 70% by weight polymer, 24. A fluid polymer/polyol as claimed in claim wherein the polymer contains from 50 to 100% styrene molar basis. DATED this 14th day of September 1990 POLYOL INTERNATIONAL B.V. By their Patent Attorneys GRIFFITH HACK CO. 1 .317"S/JM -1 21 22 23 on a